I would say....
Obviously 83 stamped F&F
and then...
Believe it or not for an 83 model original shape stainless steel bars not pro-class at this point
Takagi spider (stamped mongoose)
Takagi chainwheel
mongoose stamped crank 175mm
SR pedals P-468
mongoose stamped BB & Headset
alloy pro-class rims (with SR hubs)
fairly sure mongoose switched to cheng shin skin wall compIII's thick/thin at this point too
MX1000 copy pro-class calipers chrome
Lee Chi Tech 3 levers chrome
Pro-Class MX hinged seat clamp chrome (DC copy)
Viscount aero seat (with "BMX aero" stamped on the side rather than "viscount aero" and "mongoose" tail decal rather than "viscount")
pro-class stem (made by acs, it has "pro-class" stamped in the top although some early ones have "mongoose" stamped in the top instead)
team mongoose grips (if you want to be really anal the early grips up to 82 had 7/8" stamped on them whereas 83 onwards had "taiwan" stamped on them and are about 2mm longer - the repops that you can buy are a mold of the 83 onward grips and have an "R" stamped on them to identify them)
mongoose flight pads (with the mongoose character face, rather than the more frequently seen padset with the yellow/orange text which were on 84 onwards models. Also worthy of note is that the originals have pinky red foam whereas most repops have grey)
Right think that just about covers it - not really into mongoose much me